Spring-set air-release parking brakes, also referred to as spring brakes, are commonly utilized in trailers and heavy duty over-the-highway trucks and the like. Various valve assemblies have heretofore been specially designed and used to obtain desired operational characteristics for these spring brakes, as hereinafter set forth. Such valve assemblies are in most instances capable of providing these operational characteristics.
Such prior valve assemblies, however, are beset with one or more shortcomings. These include the fact that a) the valve assembly embodies an inordinate number of components; b) the assembly is of complex and bulky construction; c) the assembly is difficult to integrate with other existing braking components of the vehicle; and d) the assembly is unduly costly.